Fix Prettier check failures in markdown content

[Copilot]

The failing check GitHub Actions job was caused by Prettier rejecting a small set of markdown content files. This updates those files so the formatter passes without changing the intended page rendering.

• Normalize unstable frontmatter

  • Simplifies the empty more_info field in /about so repeated Prettier runs stop introducing extra blank lines.

• Preserve markdown constructs that Prettier would rewrite incorrectly

  • Adds <!-- prettier-ignore --> before the mailing-address definition list in _pages/contact.md.
  • Adds <!-- prettier-ignore --> before the manually aligned media tables in _posts/2021-09-22-remote-sim2real-trifinger.markdown.

• Scope

  • Limits the change to the files implicated by the formatter failure; no workflow or application logic changes.

Example:

<!-- prettier-ignore -->
**Prof. Animesh Garg**
: CODA 11th Floor, Office S1145  
  756 West Peachtree Street  
  Atlanta, GA 30308

[github-actions]

Failed prettier code check. Check this file for more information.